Kudankulam Nuclear Power Plant, Tamil Nadu, India

The Kudankulam Nuclear Power Plant (KNPP) is located 650km south of Chennai, in the Tirunelveli district of Tamil Nadu, India. It is being developed by the Nuclear Power Corporation of India (NPCIL).

Two 1,000MW pressurised water reactor (PWR) units based on Russian technology were erected in phase one of the project. An additional four units are scheduled to be added according to the agreement signed between India and Russia in December 2008.

Excavation works for the construction of units three and four started in 2016 with the aim of making them operational by March 2021.

Atomstroyexport, a subsidiary of the Russian State Nuclear Energy Corporation Rosatom, is the supplier of equipment and fuels for the nuclear power project.

Kudankulam nuclear power plant construction and protests

"Two 1,000MW pressurised water reactor units based on Russian technology form part of the first phase of the project."

Concrete work for units one and two started in March 2002 and July 2002, respectively. NPCIL started commercial operations of unit 1 from midnight of 31 December 2014, while unit two was synchronised with the southern grid in August 2016.

The construction work on-site was stopped in October 2011 because of protestors. However, it resumed in March 2012 with the permission of the Tamil Nadu government.

In May 2013, the Indian Supreme Court dismissed the petitions by nuclear activists questioning the safety of the nuclear power plant and granted the go-ahead for the commissioning of the first two units.

However, the Atomic Energy Regulatory Board (AERB), NPCIL and the Department of Atomic Energy of India have been asked by the court to ensure the safety of the plant and give final clearances before the start of commercial operations.

Controversy regarding KNPP

Kudankulam NPP has been a controversial project since its inception, with protests by local residents and various activist groups over potential radiation threats and issues related to nuclear waste disposal.

The anti-Kudankulam campaign intensified after the Fukushima nuclear incident in Japan in 2011.

KNPP is allegedly located in a tsunami prone area and more than one million people residing within the 30km radius of the nuclear power plant cannot be evacuated safely in the occurrence of any nuclear disaster.

The People's Movement Against Nuclear Energy (PMANE) is at the forefront of the anti-Kudankulam campaign.

Identification of four faulty crucial valves in reactors at Kudankulam and the arrest of Russian officials for sourcing substandard materials for nuclear equipment further fuelled opposition to the plant.

Kudankulam nuclear power plant details

NPCIL and Rosatom finalised the reactor design and engineering supervision arrangements for the construction of KNPP phase one in 1998, which cost Rs140bn ($2.47bn).

"Kudankulam NPP has been a controversial project since its inception, with protests by local residents and various activist groups."

Construction of phase one started in 2001 and the first two units of were originally scheduled for commissioning in December 2007 and December 2008 respectively.

The project has, however, experienced significant delays because of persistent protests by locals and nuclear activists over safety concerns.

Kudankulam NPP has a production life of 60 years, which can be extended by another 20. The first unit of the plant supplies power at a cheaper rate of about Rs3.89 per unit.

The home state Tamil Nadu is allocated 50% (925MW) of the power generated, while the neighbouring states share 35% of the residual power, including 442MW for Karnataka, 266MW for Kerala and 67MW for Puducherry. The other 15% of the generated power is unallocated and is added to a central pool.

KNPP reactor

Kudankulam, or Koodankulam, is India's first nuclear plant to use imported PWR technology. The existing nuclear power plants in India use pressurised heavy water reactor or boiling water reactor technology.

KNPP uses the advanced version of Russian-developed PWR nuclear technology, VVER-1000 type reactors, also known as water-water power reactors.

VVER technology has completed more than 1,500 reactor-years of operating time.

KNPP uses AES-92, also called the V-466 model, which is the latest version of the third-generation VVER-1000. This integrates active and passive safety measures, including passive heat removal system (PHRS), hydrogen re-combiners, core catcher, hydro accumulators and quick boron injection system (QBIS). This multi-layered safety feature ensures the plant and environment are safe.

Safety features

The AES-92 includes a combination of active and passive safety solutions. It retains the traditional active safety provisions such as the use of neutron absorbing control rods to control the reactivity.

The passive safety relies on natural factors such as pressure differentials, gravity or natural convection, to ensure protection against malfunctions during emergency situations.

This include the fast injection of high-pressure boron and the provision of extra tanks for long-term supply of borated water to the reactor in a passive way, as well as a system for inter-containment area passive filtration.

The reactor building has a series of passive hydrogen re-combiners to convert abnormal production of hydrogen into water. This also includes a system for containing the molten-core of the reactor during severe accidents.

AES-92 has a double protective containment with the inner envelope made of steel and the outer one made of heavy reinforced concrete steel. This prevents radioactive release into the environment during possible disasters, including earthquakes, tornadoes or aircraft crash. The inner containment is equipped with a water sprayer system to ease the steam pressure in the reactor.

KNPP contractors

Atomstroyexport is responsible for the technical design, construction supervision and technical support for reactor commissioning, as well as training for operation and maintenance and the supply of equipment and materials.

Bharat Heavy Electricals configures the machines at the plant and NPCIL undertakes the construction, erection and commissioning.

The Rajasthan Atomic Power Project (RAPP), located in Rawatbhata in the north Indian state of Rajasthan, currently has six pressurised heavy water reactor (PHWR) units operating with a total installed capacity of 1,180MW.